diff options
Diffstat (limited to 'libgo/go/image/names.go')
-rw-r--r-- | libgo/go/image/names.go | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/libgo/go/image/names.go b/libgo/go/image/names.go new file mode 100644 index 0000000000..c309684cea --- /dev/null +++ b/libgo/go/image/names.go @@ -0,0 +1,67 @@ +// Copyright 2010 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package image + +var ( + // Black is an opaque black ColorImage. + Black = NewColorImage(Gray16Color{0}) + // White is an opaque white ColorImage. + White = NewColorImage(Gray16Color{0xffff}) + // Transparent is a fully transparent ColorImage. + Transparent = NewColorImage(Alpha16Color{0}) + // Opaque is a fully opaque ColorImage. + Opaque = NewColorImage(Alpha16Color{0xffff}) +) + +// A ColorImage is an infinite-sized Image of uniform Color. +// It implements both the Color and Image interfaces. +type ColorImage struct { + C Color +} + +func (c *ColorImage) RGBA() (r, g, b, a uint32) { + return c.C.RGBA() +} + +func (c *ColorImage) ColorModel() ColorModel { + return ColorModelFunc(func(Color) Color { return c.C }) +} + +func (c *ColorImage) Bounds() Rectangle { return Rectangle{Point{-1e9, -1e9}, Point{1e9, 1e9}} } + +func (c *ColorImage) At(x, y int) Color { return c.C } + +// Opaque scans the entire image and returns whether or not it is fully opaque. +func (c *ColorImage) Opaque() bool { + _, _, _, a := c.C.RGBA() + return a == 0xffff +} + +func NewColorImage(c Color) *ColorImage { + return &ColorImage{c} +} + +// A Tiled is an infinite-sized Image that repeats another Image in both +// directions. Tiled{i, p}.At(x, y) will equal i.At(x+p.X, y+p.Y) for all +// points {x+p.X, y+p.Y} within i's Bounds. +type Tiled struct { + I Image + Offset Point +} + +func (t *Tiled) ColorModel() ColorModel { + return t.I.ColorModel() +} + +func (t *Tiled) Bounds() Rectangle { return Rectangle{Point{-1e9, -1e9}, Point{1e9, 1e9}} } + +func (t *Tiled) At(x, y int) Color { + p := Point{x, y}.Add(t.Offset).Mod(t.I.Bounds()) + return t.I.At(p.X, p.Y) +} + +func NewTiled(i Image, offset Point) *Tiled { + return &Tiled{i, offset} +} |